The present invention relates generally to exposure devices, and more particularly to a manufacturing device and method of the exposure device. The present invention is suitable, for example, for a manufacturing device and method of an exposure device for use with an electrophotographic recording device. The xe2x80x9celectrophotographic recording devicexe2x80x9d by which we mean is a recording device employing the Carlson process described in U.S. Pat. No. 2,297,691, as typified by a laser printer, and denotes a nonimpact image-forming device that provides recording by depositing a developer as a recording material on a recordable medium (e.g., printing paper, and OHP film). The image-forming device is a concept that broadly covers not only a discrete printer, but also various apparatuses having a recording function such as a photocopier, a facsimile unit, a computer system, word processor, and a combination machine thereof.
With the recent development of office automation, the use of electrophotographic recording devices for computer""s output devices, facsimile units, photocopiers, etc. has spread steadily. The electrophotographic recording device features good operability, usability for a wide range of media, high cost efficiency, and high-quality and high-speed printability, and reduced noise in a printing operation; thus a further increase in demand will be expected in future.
The electrophotographic recording device typically includes a photosensitive drum and an exposure device, and follows a process constituting the steps of charging, exposure to light, development, transfer, and other post-processes, to form a desired image. These procedural steps of forming an image are basically followed by either a single color or multicolor electrophotographic recording device.
In a charging step, a pre-charger electrifies the photosensitive drum uniformly (e.g., at xe2x88x92600 V). In an exposure step, the exposure device irradiates a light on the photosensitive drum, and varies a potential on an irradiated area, for example, to xe2x88x9250 V or so, to form an electrostatic latent image. In a development step, a development device electrically deposits a developer onto the photosensitive drum, and visualizes an electrostatic latent image. In a transfer step, a transfer device transfers a toner image onto a recording medium by adsorbing the toner image formed on the photosensitive drum onto a sheet of printing paper by an electrostatic adsorption. In a fixing step, the fixing device fuses and fixes the toner image formed on the medium by applying heat, pressure or the like, and forms a final image on the medium. The post-processes may include charge neutralization and cleaning on the photosensitive drum from which toner has been transferred out, a collection and recycle and/or disposal of residual toner, etc.
Among the above-described devices for an image formation, the exposure device as an optical system for writing operation includes a light source and an image-forming member that directs a beam of light irradiated from the light source onto the photosensitive drum so as to form an image. The optical system for writing operation may adopt the following two methods. One is a mechanical scanning method that employs a laser as a light source, and scans by mechanically polarizing the beam of light using a variety of mirrors. The other is a solid state scanning method that employs a light-emitting device or the like as a light source, and scans by forming an array from the light source itself or a shutter provided in front of the light source, and distributing exposure data to each device. In recent years, the solid state scanning method has been in the mainstream, which employs, as a light source, an LED array having as many LED chips as recording pixels arranged in tandem, each LED chip having a plurality of LEDs. In addition, as an image-forming member for the above method, an unmagnified erect image projection lens array that projects an unmagnified erect image from the LED has been receiving attention in recent years.
The exposure device that adopts this solid state scanning method typically includes an LED array, an unmagnified erect image projection lens array, a lens array support, and a frame. Light irradiated from the LED in the LED array needs aligning with an optical axis of a lens in the unmagnified erect image projection lens array, and forming an appropriate image on the photosensitive drum. Thus, the LED array and the unmagnified erect image projection lens array are arranged to conform with the conditions. The lens array support securely supports the unmagnified erect image projection lens array, and the frame securely holds the LED array and the lens array support. The unmagnified erect image projection lens array is typically composed of a plurality of optical fibers as lenses, which are arranged in tandem. The lens array support includes a groove to which the unmagnified erect image projection lens array is to be fitted.
To manufacture this exposure device, typically, the LED array and the lens array support are fastened on the frame, and then the unmagnified erect image projection lens array is fitted and bonded to the lens array support with an adhesive. A securing process of the unmagnified erect image projection lens array, to be more specific, comprises the steps of adjusting a tilt and fitting depth of the unmagnified erect image projection lens array by controlling a manufacturing device to conform with the above conditions after fitting and before bonding with an adhesive the unmagnified erect image projection lens array to the lens array support. The manufacturing device integrally incorporates a holding member that holds the unmagnified erect image projection lens array, a plurality of CCD cameras fastened at several spots (e.g., five spots) along a top of the unmagnified erect image projection lens array, and an actuator that moves the holding member up or down and makes it tilted. The tilt and the fitting depth of the unmagnified erect image projection lens array are adjusted so as to conform with the above conditions by utilizing a plurality of the CCD cameras.
However, the aforementioned conventional manufacturing device and method of the exposure device has a number of disadvantages. First of all, an integration of the holding member, the CCD camera, and the actuator requires a long-time operation. For example, the above components of the exposure device cannot be detached from the manufacturing device until the adhesive is cured, whereby the number of the exposure devices that can be manufactured within limited time cannot be increased. Second, the actuator as conventionally provided introduces a tilt on the holding member by pivoting the same on a point of intersection of an LED-side end surface and optical axis of the lens, and the tilt brings a misalignment of the LED out of the optical axis of the lens, thereby preventing a sharply defined image from being formed, and degrading an image quality. Moreover, the conventional actuator is designed to make an adjunctive correction by a tilt on the lens to supplement a correction made by a horizontal movement of the lens, thereby making it more and more difficult to form a sharply defined image. Thirdly, The manufacturing device as conventionally provided has no means for observing a state of image formation other than where the CCD camera is placed, and thus has no chance to correct deformations of the unmagnified erect image projection lens array that would become wrenched or wavy along the length, preventing a sharply defined image from being formed, and degrading an image quality as well.
Therefore, it is an exemplified general object of the present invention to provide a novel and useful manufacturing device and method of an exposure device, in which the above conventional disadvantages are eliminated.
Another exemplified and more specific object of the present invention is to provide a manufacturing device and method of an exposure device that can manufacture a high-performance development device in a short time.
In order to achieve the above objects, a manufacturing device of an exposure device including a light source and an unmagnified erect image projection lens array as one exemplified embodiment of the present invention comprises a first holding member that holds the light source in the exposure device, a second holding member that holds the unmagnified erect image projection lens array in the exposure device, and an actuator that is connected with the first and second holding members and moves at least one of the first and second holding members to position the unmagnified erect image projection lens array relative to the light source, wherein at least one of the first and second holding members can be attached to and detached from the actuator. In such a manufacturing method of the exposure device, at least one of the first and second holding members can be attached to and detached from the actuator while holding the light sources or the unmagnified erect image projection lens array. This would allow at least one of the holding members to be detached from the actuator and to perform in any other place processes that take much time after the unmagnified erect image projection lens array is positioned relative to the light source (e.g., a bonding step and processes thereafter), so that the manufacturing device could be used for another exposure device. In this manner, the manufacturing device can achieve a reduction of whole manufacturing time by reducing and eliminating its quiescent time.
A manufacturing device of an exposure device including a light source and an unmagnified erect image projection lens array as another exemplified embodiment of the present invention comprises a first holding member that holds the light source in the exposure device, a second holding member that holds the unmagnified erect image projection lens array in the exposure device, a correction mechanism that may displace one of the first and second holding members with respect to the other at least in three directions, and an actuator that is connected with the first and second holding members and drives the correction mechanism to position the unmagnified erect image projection lens array relative to the light source. This manufacturing device includes the correction device for displacing one of the first and second holding members with respect to the other in three dimensions, and may thus provide a higher-quality exposure device than a conventional manufacturing device that cannot displace only in two directions.
A manufacturing device of an exposure device including a light source and an unmagnified erect image projection lens array as still another exemplified embodiment of the present invention comprises a first holding member that holds the light source in the exposure device, a second holding member that holds the unmagnified erect image projection lens array in the exposure device, a correction mechanism that may displace one of the first and second holding members in a direction perpendicular to both an optical axis and longitudinal direction of the unmagnified erect image projection lens array, and an actuator that is connected with the first and second holding members and drives the correction mechanism to position the unmagnified erect image projection lens array relative to the light source. This manufacturing device can displace any one of the first and second holding member in a direction perpendicular to both an optical axis and longitudinal direction of the unmagnified erect image projection lens array, and may thus provide a higher-quality exposure device than a conventional manufacturing device.
A manufacturing method of an exposure device including a light source and an unmagnified erect image projection lens array as an exemplified embodiment of the present invention comprises the steps of providing the light source for use with the exposure device on a first holding member connected with an actuator, providing the unmagnified erect image projection lens array for use with the exposure device on a second holding member connected with the actuator, positioning the unmagnified erect image projection lens array relative to the light source by driving the actuator, bonding the unmagnified erect image projection lens array on a lens array support, and detaching at least one of the first and second holding members from the actuator. According to the present manufacturing method, any one of the first and second holding members can be detached from the actuator. Therefore, for instance, in processes after a bonding step, at least one of the holding members can be detached from the actuator, and an adhesive is dried in any other place, meanwhile manufacturing process up to the bonding step may be performed for another exposure device. In this manner, according to this manufacturing method, a downtime of the device would be reduced or eliminated, whereby whole manufacturing time would be reduced.
A manufacturing method of another exposure device including a light source and an unmagnified erect image projection lens array as an exemplified embodiment of the present invention comprises the steps of providing the light source for use with the exposure device on a first holding member connected with an actuator, providing the unmagnified erect image projection lens array for use with the exposure device on a second holding member connected with the actuator, positioning the unmagnified erect image projection lens array relative to the light source by driving the actuator in such a manner as to displace one of the first and second holding members with respect to the other at least in three directions. This manufacturing method includes the correction mechanism for displacing one of the first and second holding members with respect to the other at least in three directions, and can thus provide a higher-quality exposure device than a conventional manufacturing device that can only displace it in two directions.
Other objects and further features of the present invention will become readily apparent from the following description of the embodiments with reference to accompanying drawings.